Valve Machining Precision Requirements

Dimensional accuracy: In manifold block machining, the dimensional accuracy requirements for holes are relatively high. Different fit requirements correspond to different tolerance grades. For example, 0T2-T18 is used for dimensions with no fit requirements, 7-T8 is used for fit dimensions with high precision requirements, and 06 is used for precision fit dimensions of important parts, etc.

Geometric tolerances: The perpendicularity tolerance among the six surfaces of the manifold block should preferably be 0.05mm, and must not exceed 01m; the parallelism tolerance between opposite surfaces (i.e. parallel planes) is 03mm; the flatness tolerance of each surface is 002mm; the perpendicularity tolerance between the thread and its mating surface is 0.05mm.

Surface roughness: The roughness of the sealing surface of the end pipe joint and the O-ring groove shall not exceed Ra3.2; the roughness of general oil passage holes shall not exceed Ra12.5. The mating surfaces between blocks must not have obvious scratches.

Other requirements: The surface of qualified parts should have a certain degree of precision and finish; the more important the part, the higher the precision requirement. Mating components such as the hydraulic control valve block and valve stem, and the valve spool and sleeve in the full hydraulic steering unit, undergo special machining during manufacturing and are pair-ground for a very precise fit.

In summary, during manifold block machining, dimensional accuracy, geometric tolerances, and surface roughness must be strictly controlled to ensure the quality and performance of the final product.

Dimensional accuracy: In manifold block machining, the dimensional accuracy requirements for holes are relatively high. Different fit requirements correspond to different tolerance grades. For example, 0T12-T18 is used for dimensions with no fit requirements, 7-T8 is used for fit dimensions with high precision requirements, and I6 is used for precision fits of important parts

dimensions, etc.

Geometric tolerances: The perpendicularity tolerance among the six surfaces of the manifold block should preferably be 005mm, and must not exceed 01m; the parallelism tolerance between opposite surfaces (i.e. parallel planes) is 003mm; the flatness tolerance of each surface is 002mm, and the perpendicularity tolerance between the thread and its mating surface is 0.05mm.

Surface roughness: The roughness of the sealing surface of the end pipe joint and the O-ring groove shall not exceed Ra3.2; the roughness of general oil passage holes shall not exceed Ra2.5. The mating surfaces between blocks must not have obvious scratches. Other requirements: The surface of qualified parts should have a certain degree of precision and finish; the more important the part, the higher the precision requirement. Mating components such as the hydraulic control manifold block and valve stem, and the valve spool and sleeve in the full hydraulic steering unit, undergo special machining during manufacturing and are pair-ground

for a very precise fit.